Spinning of artificial filaments



v UNITED ST TES -sl'lNNlNG oran'rmcmnmmm'rs- Camille nmm, New York, N. x. and wnusm Whitehead. Cumberland, Md., assignors to Celanesc Corporation of America, a corporation of Delaware No Drawing. Application November 27, 1929,

Serial Claims. (01. 10-54) This invention relates to the preparation of yarns containing filaments of fine size and made of organic derivatives of cellulose.

. An object of our invention is to make filaments of organic derivatives of cellulose of finer size than has been heretofore possible. Another object of ourinvention is to make fine filaments by extruding a solution containing an organic derivative of cellulose and a compound of the polyhydric alcohol class through fine orifices into a precipitating fiuid' and drawing out or stretching the filaments thus formed. Other objects of our invention will appear from the following detailed description. v 4

The preparation of artificial filaments of very e size or denier is often highly desirable since or fabrics made from such finefilaments have many excellent properties as to luster, feel, hand, softness and the like. Heretofore it has not been possible to produce filaments of organic derivatives of cellulose that are appreciably finer than two denier. We have found that if a compound of the polyhydric alcohol class is added to or incorporated in a solution of 'a derivative of cellulose in a suitable solvent, it is possible to spin filaments having deniers as low as 0.70 or less from such solutions.

In accordance with our invention we prepare filamentsof low denier and yarns containing such filaments by extruding a solution containing an organic derivative of cellulose, a suitable solvent and a compound of the polyhydric alcohol class through orifices of suitable size and shape into a 'fiuidcausing the solidification of the filaments, while drawing out or stretching the filaments so formed whereby filaments of the desired fineness are formed,

- Any suitable organic derivatives of cellulose such as organic esters of cellulose or cellulose ethers may be employed for making the filaments. Examples of organic esters of cellulose are cellulose acetate, cellulose formate, cellulose propionate and cellulose butyrate while examples of cellulose ethers are ethyl cellulose, methyl cellulose and benzyl cellulose. However, we prefer to employ an acetone soluble cellulose acetate and generally 1 the solutions employed for spinning contain from 15 to 30% by weight of such cellulose acetate.

As stated the spinning solution contains a compound of the polyhydric alcohol class. The term "compound of the polyhydric alcohol class" in-.

cludes not only the .polyhydric alcohols but also their derivatives such as ethers or esters thereof. Examples of polyhydric alcohols are the glycols such as diethylene glycol or ethylene glycol and also glycerol and diglycerol. Examples of ethers of. polyhydric alcohols are the mono methyl ethers of ethylene glycol -or of difrom 2 to 20% of the weight of the cellulose acetate or other organic derivative of cellulose. In making the spinning solution any suitable solvent for the derivative of cellulose may be employed. We prefer to employ acetone or mixtures of acetone and water, acetone and ethyl alcohol, or acetone and methyl alcohol. The proportions of acetone in such mixtures may vary from, '75 to 100% of the weight of the solvent mixture employed. However, other solvents or solvent mixtures may be employed, examples of which are mixtures of methylene chloride and ethyl or methyl alcohol and mixtures of ethylene dichloride and methyl or ethyl alcohol.

The spinning jets through which the solution of the derivative of cellulose is extruded may have any suitable number of orifices, say from 10 to 100 depending upon the number of filaments in and the denier of the yarn to be made. These orifices may have any shape although we prefer to use circular orifices. As to the size of the orifices, this may be varied in accordance with the fineness of the filaments to be formed, varying from 0.04 to 0.15 mm. diametenj I In order to form the filaments, the solution of the derivative of cellulose is extruded through orifices into a drying evaporative atmosphere, as in dry spinning,-or into a pre'cipitatingnor' coagulating liquid bath as inwet spinning,

While the filaments are formed, they are preferably drawn out or stretched in order to reduce their size or denier. This stretching is preferably performed within the spinning machine, while the filaments are passing from the orifices where they are formed-to a feed roller or outside thereof, and may be done by any suitable mechanical means. Thus the filaments may be passed around rollers rotating at progressively increasing peripheral speed and thus stretched.

By our invention filaments of very fine size may be made having deniers as low as 0.70 to 1.80. By varying such factors as the amount of polyhydric alcohol compound employed, concentration of the derivative of cellulose in'the spinning solution, the size 01' the spinning jet orifices and the amount of stretch imparted to the filaments,

.1 filaments of 0.70, 0.80, 0.90, 1.00, 1.20, 1.40, 1.60 or 1.80 denier may be made.

The filaments formed may be associated together by twisting into yarn oi the desired denier, and this twisting may be done as a separate operation or in conjunction with winding the filaments as they are formed. Yarns made in this manner often have greater strength and pllabllity than yarns previously made. Such yarns may be employed to make woven, knitted or netted fabric consisting wholly of such yam or containing such yarn and yarn of other fibres such as cotton, silk or wool. The filaments so formed may be cut into short lengths orstaples which may be associated together by twisting to form "spun" yarn. If desired the compound of the polyhydric alcohol class employed may be removed from the yarns or the fabrics made therefrom by washing with water or other aqueous liquids such as ordinary scouring and dyeing baths.

In order further to illustrate our invention but without being limited thereto, the following specific examples are given.

Example I A solution oi an acetone soluble cellulose acetate having an acetyl value 01' 54 to 55% is made by dissolving one part of the cellulose acetate in 3 parts oi a solvent mixture consisting of 95 parts of acetone and 5 parts of water. To this solution there is added diethylene glycol in amounts equal to 5% of the weight of the cellulose acetate present. Alter thorough mixing, the solution is filtered and is extruded through circular orifices of 0.08 mm. diameter into a drying evaporative atmosphere. The filaments thus formed are then stretched by being passed to rollers rotating at relatively high peripheral speed, and the filaments thus formed are associated together by twisting to form yarn. Filaments having a denier or 1.40 are formed in thismanuer.

If instead 01' employing a mixture of 95 parts of acetone and 5 parts of water as the solvent, a mixture of 80 parts of acetone and 20 parts of water is employed, filaments having a denier or 1.07 are formed.

Example II On: part 01' the cellulose acetate defined in Example I is dissolved in 4 parts of a solvent mixture comprising parts of acetone and 10 parts 01' water. To this solution there is added diethylene glycol in amounts equal to 5% of the weight of the cellulose acetate present. In spinning this solution through jets having orifices of 0.06 mm.

00 diameter, filaments of .95 denier are formed.

11' jets having orifices of 0.05 mm. diameter are employed and the solvent mixture used contains 80 parts of acetone and 20 parts of water, filaments having deniers as low as 0.70 are formed.

05 Example III The same cellulose acetate employed in Example I is dissolved in a solvent mixture consisting of parts of acetone and 5 parts of alcohol.

70 One part of the cellulose acetate is dissolved in 3 parts by weight of the solvent mixture and to this is added diethylene glycol in amounts equal to 5% 01' the weight of the cellulose acetate. When this solution is spun in the manner described in Iixamplel filaments of 1.70 denier are formed. 1!

the mono ethyl ether of diethylene glycol insubstituted for the diethylene glycol substantially the same results are attained.

It is to be understood that the foregoing detailed description is given merely by way oi illustration and that many variations may be made therein without departing from the spirit oi this invention.

Having described our invention what we claim and desire to secure by Letters Patent is:

1. Method of forming fine filaments. which comprises forming a solution or an organic derivative oi cellulose in a suitable solvent mixture containing an ether of a polyhydric alcohol in an amount equal to 2-20% on the weight of the organic derivative 01' cellulose, forming said solution into filaments by extruding it through orifices into a setting medium which causes solidification oi the extruded filaments without removing said ether, and stretching the filaments thus formed.

2. Method of ,forming fine filaments. which comprises forming a solution of cellulose acetate in a suitable solvent mixture containing an ether of polyhydric alcohol in an amount equal to 2-20% on the weight of the cellulose acetate. forming said solution into filaments by it through orifices into a setting medium which causes solidification of the extruded filaments without removing said ethe and stretching the filaments thus formed.

3. Process for the production 01' artificial filaments of low denier which comprises extruding a solution 01' an organic derivative of cellulose in a solvent mediumcontaining a volatile solvent i'or the cellulose derivative, in amount from 5 to 25% on the weight of the solvent mixture of a non-solvent for the cellulose derivative and 2-20% on the weight 01 the cellulose derivative of an ether of a polyhydrlc alcohol. through suitable orifices into an evaporative atmosphere which does not evaporate all of said ether, and stretching the filaments so i'ormed.

4. Process for the production 01' artificial filaments of low denier which comprises a solution of cellulose acetate in a solvent medium containing acetone, in amount from 5 to 25% on the weight of the solvent mixture 01' waterand 2-20% on the weight of the cellulose acetate 01 an ether of a polyhydrlc alcohol, through suitable orifices into an evaporative atmosphere which does not evaporate all of said ether, and stretching the filaments so formed until they have a size less than 1.8 denier.

5. Process for the production of artificial filaments or low denier which comprises extruding a solution oi cellulose acetate in a solvent mixture containing an ether of a polyhydric alcohol which is a non-solvent for the cellulose acetate in an amount equal to 2-20% on the weight of cellulose acetate present, through suitable orifices into an evaporative atmosphere which does not evaporate all 01' said ether, and st the filaments so formed less than 1.8 denier.

6. Process for the production of artificial filaments of low denier which comprises extruding a solution of cellulose acetate in a solvent medium containing the mono-ethyl ether of diethylene glycol in amount equal to2-20% on the weight of the cellulose acetate, through suitable orifices into an evaporative atmosphere which does not evaporate all of said ether. and stretching the filaments so formed un they have a side less than 1.8 denier.

retching until they have a sine 'hmamentsotorganicderlvativeepfcellulose oflessthanlfidenlerandthemonohavlngaaiaeotlessthanlx denier and conethyletherotdlethyleneglwol. um am talnlnganetherotapolyhydrlc alcohol. 10. oi'cellulmemeta vmg Ono- 8.1"llamentsotcelluloseacetatehavlngasize oi'lessthanlfldemermd m 6 5 lessthanlfidenierandoontainlnsanetherot ethyletherordiethyleneglyeol.

poly dric alcohol. c Cm YFUB. ll 'l limentsofcelhfloeeacetatehavinsasiae WILLIAM HI CERTIFICATE or CORRECTION.

'Patent No. 2,072,100. March 2. 1937.

CAMILLE DREYFUS', ET AL. 1

It is hereby certified that error appears in the printed specification or the above numbered patent requiring correction as follows: Page 2, second column, line 25, claim 2, after the word "of" insert a; line 75, claim 6, for "side" read size; and that the said Letters Patent should be read with these corrections therein that the same may conformto the record of the case in the Patent Office.

Signed and sealed this 30th day of March, A. D. 1-937.

Henry-Van Arsdale (Seal) Acting Commissioner of Patents.

' 'hmamentsotorganicderlvativeepfcellulose oflessthanlfidenlerandthemonohavlngaaiaeotlessthanlx denier and conethyletherotdlethyleneglwol. um am talnlnganetherotapolyhydrlc alcohol. 10. oi'cellulmemeta vmg Ono- 8.1"llamentsotcelluloseacetatehavlngasize oi'lessthanlfldemermd m 6 5 lessthanlfidenierandoontainlnsanetherot ethyletherordiethyleneglyeol.

poly dric alcohol. c Cm YFUB. ll 'l limentsofcelhfloeeacetatehavinsasiae WILLIAM HI CERTIFICATE or CORRECTION.

'Patent No. 2,072,100. March 2. 1937.

CAMILLE DREYFUS', ET AL. 1

It is hereby certified that error appears in the printed specification or the above numbered patent requiring correction as follows: Page 2, second column, line 25, claim 2, after the word "of" insert a; line 75, claim 6, for "side" read size; and that the said Letters Patent should be read with these corrections therein that the same may conformto the record of the case in the Patent Office.

Signed and sealed this 30th day of March, A. D. 1-937.

Henry-Van Arsdale (Seal) Acting Commissioner of Patents. 

